Hot top



Jan. 19, 1965 M. D. LA BATE 3,165,797

HOT TOP Filed Jan. 8, 1963 INVENTOR.

Micheal Donald La Baze BYW/ a ATT RNEY.

United States Patent 3,165,797 HGT T3? Micheal Donald La Bate, Kay 5t, Wampum, Fa. Filed .lan. 8, 1953:, Ser. No. 250,945 5 Claims. (Cl. 22147) This invention relates to 'hot tops used in conjunction with ingot molds to form a heat retaining extension at the top of the mold which serves to retain a bathcf molten metal at the top of the mold during the freezing of the ingot. The effect is to prevent or minimize piping and the formation of other defects in the head of the ingot.

The principal object of the invention is the provision of a hot top formed of four tapered wall sections incor- A still further object of the invention is the provision of a consumable hot top incorporating consumable material adapted to produce a temperaturewhen burning less than that of the hot metal contained in the hot top:

The improved hot top hereinafter disclosed has a number of advantages as compared to prior art hot tops and these are combustibility, lightness which permits the saving in the labor of placing the hot tops, ease of manufacture from inexpensive materials with direct production economy, marked increase heat insulating and supplying characteristics and the-desirable characteristic of being consumed after it has served its purpose in maintaining a pool of molten metal at the top of, the ingot being formed.

Most hot tops used in pouring of metal ingots as, for example, in the steel industry, have heretofore comprised hot tops formed of ceramic materials and it is we ll'known that such hot tops are heavy, difiicult to position, fragile when handled and often permit the chilling of the metal in the hot top to proceed at a rate comparable with that in the body of the ingot mold which thereby considerably reduces their effectiveness in maintaining a pool of molten metal to preclude the formation ofpiping and other de fects in the chilling ingot. Consumable hot tops as heretofore known in the art have required an extremely careful application to an ingot mold and the pouring of molten metals within a specified temperature range in order that the consumable hot tops would be etfective in use.

The present invention overcomes-the several diiiiculties and provides a consumable hot top which is relatively light in weight, easy to handle, relatively indestructible and is assembled as a unitary structure only when it is positioned on or partly within an ingot mold. The device includes means comprising rods "formed integrally with each of the four tapered wall sections and registering slots in the opposite ends of each of the sections so'that the hottop formed of the four sections-with the rods extending outwardly of the ends thereof will be self-securing in assembly and at the same time the rods serve. as a' ice it being the intention to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

The invention is illustrated in the accompanying drawing wherein:

FIGURE 1 is a side elevation of a hot top formed in accordance with the invention.

FIGURE 2 is a bottom view of the hot top shown in FIGURE 1.

FIGURE 3 is a vertical section through a portion of a hot top, on a reduced scale and a portion of an ingot mold with metal positioned therein. a

By referring to the drawings and FIGURE 1 in particular, it will be seen that the'hot top comprises a tapered body'having open upper and lower ends and consisting of four sections 1%}, i1, 12 and 13 respectively. (See also FIGURE 2 of the drawings.) Each of the sections 19, 11, i2 and Hate identical so that only one master shape need be made and that four sections of said master shape can be assembled to form the four sided upwardly tapered hot top as seen in FIGURE 1 of the drawings.

By referring thereto, it will be seen that a full side elevation of one such section indicated by the numeral 19 is disclosed and it'will be seen that it has inwardly and upwardly angled marginal openings 14, 14' in its left wardly beyond the face of the section 11, while the lower rod' 15, it beingrelatively longer, does extend outwardly of the face' of the section ii so that it in conjunction with three similar rods located'on the same horizontal plane in each of the other three sections 11, i2 and 13 of the hot top form means for supportingthe'assembled hot top partially within an ingot mold as seen in FIGURE 3 of r the drawings. Each of the sections 16, 11, Hand 13 of over the rod 15.

the hot top has a recess 17in its innermost surface so that when metal is poured into the ingot mold as seen in which a crane cangrasp the in ot when the same, is

stripped from the mold M, as will be understood by those skilled in the art.

Still referring to FIGURE 1 of the drawings, it will also be'seen that each of an opposed pair of the upper rods 15, 15 is provided'with a metal hook 18, the upper end of which is eyeleted and stands above the upper end of the hot top and thelower end of which. is hooked This pair of books 18thus provided enables the hot top to be assembled and picked up by a crane and'conveniently positioned on or man ingot mold.

as will occur to those skilled in the art'.

Still referring to FIGURE 1 of the drawings, it will be seen that each of the sections it}, 11, 12 and 13. of. the

hot top are provided with a notch in theirlowermo'st,

edges as indicated generally by the numerals '19, 19.

' By referringto FIGURE 2 of. the drawings, it will be seen that when four of'the sections of the hot topas shown in FIGURE 1' are positioned to form a tapered open top and bottom member, the protruding ends of the rods i5, 15 will be positioned one on each of the sections near the edge thereof and thereby form suitable means supporting the hot top on theingot mold asseen in FIG- URE 3 ofjthedrawings.

Itwill also be observed that each of the notches 19 is partially closed at its lowermost 3 edge by the bottom of a U-shaped metal strap 20, the upper ends of the arms of which are outturned as at 21 in FIGURES 1 and 3 of the drawing and embedded in the material of the consumable hot top.

By referring to FIGURE 3 of the drawings, it will be seen that when molten metal is poured into the hot top and into the ingot mold M it will rise up into the notches 19, surround the bottom portion of the U-shaped metal clip 20 and then pack it to the inner wall of the ingot mold as the metal freezes thereagainst. This action anchors the hot top in position in the upper end of the ingot mold and prevents it from floating as the fluid metal flows upwardly therein as seen in FIGURE 3 of the drawings. The material from which the hot top sections 10, 11, 12 and 13 are formed is adapted to receive and hold liquid metals at temperatures as high as 3400" F. while retaining their original shape and physical characteristics without permitting the liquid metal to escape so that the metal can solidify normally. However, after a desired time interval, the material of the hot top will ignite and be consumed and result in the formation of a powder-like residue which has no ill effect on the ingot and which, on the contrary, has maintained or helped to maintain the necessary temperature in the metal in the hot top so that as the ingot and the ingot mold cools the molten'metal can flow downwardly thereinto and prevent the formation of pipes and cracks and other undesirable irregularities therein. Several different variations in the mixture of materials used to form'the portions of the ingot mold are possible within the scope of the invention. prise a batch including 40 lbs. wood sawdust; 100 lbs. raw dolomite; 80 lbs. sodium silicate as a binder or approximately 19% wood sawdust, 45% raw dolomite and 36% sodium silicate. This basic mixture may be altered by substituting an equal quantity by weight of small wood chips, rice hulls or wheat kernels for the saw dust. A still further variation forming a suitable mix comprises substituting sintered granulated blast furnace slag or finely ground fired clay (grog) for the raw dolomite in equivalent weight. It has also been determined that the resin urea-formaldehyde in the amount of 50 lbs. by weight can be used as a binder rather than the 80 lbs. of sodium silicate.

It will occur to those skilled in the art that a number of variations in the mix of the consumable hot top mate-. rials are therefore possible.

In forming a hot top section as disclosed herein, a basic mixture of the above mentioned ingredients is made, for example, of saw dust, dolomite and sodium silicate and the respective sections 10, 11, 12 and 13 are formed thereof by molding the same therefrom. This mixture tends to dry and set and forms a reasonably durable structure capable of the intended use particularly when it is force dried or baked in a heated oven. This step is, therefore, recommended. During the formation of the individual sections 10, 11, 12 and 13 by molding the same, the rods are positioned .in the sections as are the U- shaped metal clips 20 with their outturned arms 21 and the hooks 18 which are attached to the shorter rods 15. These are conveniently positioned on a fixture in the mold when the material is shaped therein so that they are substantially embedded in the individual sections of the hot top. After these sections are baked and completely dried thereby, they are preferably banded together with steel strapping and shipped to a point of use, such as in a steel mill where they are unpacked and assembled, four sec tions to a hot top at the time they are to be positioned on the ingot mold. As hereinbefore explained, the presence of the rod 15 and the registering marginal openings 14in each of the edges of the sections 10, 11, 12 and 130i the hot top enable the same to be positioned together in An example of a desirable mix will com- 1 self-retaining relationship and picked up by the hooks 18 while in such relation, and positioned in an ingot mold whereupon the extending rods 15 adjacent the lower end will position the hot top suitably therein.

It will be seen that horizontal grooves are formed in the outer surfaces of each of the sections of the hot top so that encircling bands may be applied if desired.

It will thus be seen that a consumable hot top of novel configuration and properties has been disclosed and which hot top is capable of being formed of four identical sections with the sections including registering means for holding the hot top in assembly and simultaneously positioning the same in a desirable relation in an ingot mold. The hot top thus disclosed meets the several objects of the invention and having thus described my invention, what I claim is:

1. A sectional hot top comprising four vertically standing identical fiat slab-like sections of consumable material, each of said sections having marginal openings in one of its vertical margins, rods disposed longitudinally and horizontally in each of said sections in vertical spaced relation and with the ends of said rods extending outwardly of the other one of the vertical margins of said sections for co-operative supporting relationship with marginal openings in the vertical margin of another of said sections.

2. The sectional hot top set forth in claim 1 and wherein said sections have top ends of less width than their base and taper therebetween.

3. A sectional hot top comprising four generally rectangular slab-like sections of consumable material capable of receiving and holding liquid metal for a given time when positioned on the top of an ingot mold, each of said sections having a vertical height approximately equal to its length and having a desirable wall thickness, rods embedded lengthwise in each of said sections in spaced vertical relation, the ends of said rods extending outwardly of one of the margins of each of said sections, and each of said sections having openings in its opposite margin for the reception of the rods from an adjacent section, said sections formed of a mixture of ingredients including approximately 45% raw dolomite, approximately 36% sodium silicate and approximately 19% wood sawdust.

4. The sectional hot top set forth in claim 3 and wherein one end of the lowermost of said rods in each section projects outwardly a distance beyond the surface of the adjacent section and forms a support bracket engageable on the top of an ingot mold for holding the hot top in elevated position therein.

5. A sectional hot top comprising four vertically standing identical flat slab-like sections of consumable material, each of said sections having marginal openings in one of its vertical margins, rods disposed longitudinally and horizontally in each of said sections in vertically spaced relation and with the ends of said rods extending outwardly of the other one of the vertical margins of said sections, said marginal openings in the sides of the adjacent sections disposed for co-operative supporting relationship with said rods.

References Cited in the file of this patent UNITED STATES PATENTS 2,341,589 Anthony Feb. 15, 1944 2,946,103 Vallack July 26, 1960 3,015,139 Marburg Ian. 2, 1962' 3,103,046 La Bate Sept. 10, 1963 FOREIGN PATENTS 642,895 Canada June 12, 1962 838,676 Great Britain June 22, 1960 

1. A SECTIONAL HOT TOP COMPRISING FOUR VERTICALLY STANDING IDENTICAL FLAT SLAB-LIKE SECTIONS OF CONSUMABLE MATERIAL, EACH OF SAID SECTIONS HAVING MARGINAL OPENINGS IN ONE OF ITS VERTICAL MARGINS, RODS DISPOSED LONGITUDINALLY AND HORIZONTALLY IN EACH OF SAID SECTIONS IN VERTICAL SPACED RELATION AND WITH THE ENDS OF SAID RODS EXTENDING OUTWARDLY OF THE OTHER ONE OF THE VERTICAL MARGINS OF SAID SECTIONS FOR CO-OPERATIVE SUPPORTING RELATIONSHIP WITH MARGINAL OPENINGS IN THE VERTICAL MARGIN OF ANOTHER OF SAID SECTIONS. 